ObjectivesInvasive fungal diseases (IFDs) are increasing worldwide, highlighted by WHO’s first-ever fungal priority pathogen list in 2022. Amphotericin B (AmB) is crucial for the treatment of several IFDs, and its conventional deoxycholate formulation has been replaced in high-income countries with the liposomal AmB formulation (LAmB/AmBisome®) due to reduced adverse events, such as nephrotoxicity and anaemia.1 However, the availability and affordability of LAmB remain significant challenges in low/middle-income countries. This project investigates several key characteristics of our in-house LAmBs produced by a novel manufacturing technology (EnLAmB) benchmarking the AmBisome® and simplifying the multi-step process into a more streamlined, cost-effective method. MethodsWith a lipid and AmB composition similar to AmBisome, in-house LAmB formulations were produced using a twin-screw extruder (Three-Tec GmbH) followed by reconstitution and bath-sonication. The LAmB’s size and lamellarity were determined using dynamic light scattering (DLS) and cryogenic transmission electron microscopy (Cryo-TEM). The aggregative state of AmB in lipid bilayers was also revealed by scanning samples with a UV-spectrophotometer between 300-450 nm. In vitro release (IVR) testing of LAmB was performed using a closed-loop USP-4 apparatus-based IVR assay (ERWEKA).ResultsIn-house LAmBs produced liposomes with particle sizes comparable to AmBisome®: 90-100 nm (Figure 1a). Cryo-TEM analysis (Figure 1b) revealed a unilamellar liposomal structure formation and confirmed the size ranges produced by DLS. The UV scan of in-house LAmB showed UV absorbance comparable to AmBisome® (Figure 1c). This suggests that AmB maintains tight aggregation within the lipid bilayer, which reduces toxicity. IVR testing of AmB showed a slightly higher release rate from in-house LAmB than that of AmBisome® (Figure 1d), with similarity factors (f2) at 55, suggesting a resemblance in release dynamics to AmBisome®.Conclusions: Experimental data strongly supports the EnLAmB platform as an innovative method for producing LAmB formulations with properties comparable to Ambisome®.
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